Air distribution system



Oct. 6, 1 953 R. c. ROBERTSON 0 AIR DISTRIBUTION SYSTEM I Filed Feb. 6,194'? 2 Sheets-Sheet l INVENTOR ROBERT C. ROBERTSON ATTORNEY 6, 1953 R.c. ROBERTSON 2,654,305

AIR DISTRIBUTION SYSTEM Filed Feb; 6, 1947 2 Sheets-Sheet 2 FIG. 3;

uuununhnm BY 41 m/13 r 6 W ATTORNEY Patented Get. 6, 1953 UNITED STATESPATENT OFFICE AIR DISTRIBUTION SYSTEM Robert C. Robertson, Scarsdale, N.Y. Application February 6, 1947', Serial No. 726,906

3 Claims. 1

This invention relates to air-conditioning, and more in particular tothe distribution of air into a room (the term room here means anyenclosure) with a simultaneous mixing of the incoming air with the bodyof air in the enclosure.

An object of this invention is to provide a system whereby a stream ofconditioned air may be distributed in a controlled and dependablemanner. A further object is to provide for the mixing of a stream of airwith a body or air in a thorough and efiicient manner without theobjectionable features present in prior systems. These and other objectswill be in part obvious and in part pointed out below.

The invention accordingly consists in the features of construction,combinations of elements, arrangements of parts, and in the severalsteps and relation and order of each of the same to one or more of theothers, all as will be illustratively described herein, and the scope ofthe application of which will be indicated in the appended claims.

In the drawings:

Figure 1 is a side elevation with parts broken away of a distributorconstituting one embodiment of the invention;

Figure 2 is a fragmentary top plan View of the embodiment of Figure 1;

Figure 3 is a fragmentary vertical section of the embodiment of Figure 1with a schematic showing of the manner in which an incoming stream ofair may be distributed into and mixed with the air in a room; and

Figures 4 and 5 are fragmentary side elevations of two similarembodiments of the invention.

In the past attempts have been made to distribute air into a roomwithout causing objectionable drafts and without Stratification of theair in the room. Certain of these attempts have been somewhat successfulbut from a commercial standpoint they have certain inherent faults. Forexample, certain of these distributing systems are quite noisy and thisis objectionable in many installations. In fact, this fault has been avery serious handicap to promoting the adoption of air conditioningequipment. This noise is generally caused by turbulence in the airaccompanying changes in the direction of movement of fast moving streamsof air and also by turbulence accompanying the mixing of a stream ofincoming air with air from the room.

Proposals have been made to eliminate this noise by reducing the rate offlow of the incoming air, but this reduces the capacity and theefficiency of the system. For example, assuming that a system isdesigned for a particular installation with a specific rate of entry ofthe conditioned air, then if the rate of flow of air is reduced afterinstallation for the purpose of avoiding objectionable noise theoperating conditions are changed throughout the entire system. Thus, thereduction in the rate of flow causes the reduced amount of air which iscirculated to be cooled excessively and the incoming air is not mixedthoroughly with the air in the room. Furthermore, the excessive coolingmay cause difficulties with the refrigeration system and may cause anexcessive condensation of moisture from the air. In any event, whenexcessively cooled air is introduced into a room without thorough mixingthere are cold drafts and strata of excessively cold air in the room.

With certain of the prior systems, air distributors have been providedwhere air is drawn from the room into a mixing zone within thedistributor where the incoming air is mixed with the air from the room.Generally, these arrangements cause excessive turbulence and vibrationnoises when the system is used with any degree of efficiency;furthermore, normally the air in the room is somewhat contaminated bysmoke and other dirt, and, therefore, streams of air entering thedistributors from the room deposit dirt upon the distributor or wallsurfaces. When the air distributors are within the public view it isdesirable to maintain a clean, neat appearance, but in these priorsystems the dirt soon collects on the wall surfaces to such an extentthat this neat appearance is not maintained. Furthermore, this dirttends to collect into large pieces or agglomerates which becomedislodged and are then thrown into the room with the incoming air.

In accordance with the present invention air is distributed into a roomand is mixed with the air therein without objectionable noise.Furthermore, the mixing of the incoming air with the air in the room iscarried on in a thoroughly dependable manner without depositing dirtupon the decorated surfaces; and, the rate of flow of air into the roommay be quite substantial and the most exacting requirements ofcommercial practice may be satisfied with distributors of more or lessstandardized construction and design.

In the illustrative embodiments of the invention, the incoming stream ofair is carried through air distributing ducts to one or more distributoroutlets and the arrangement is such that the air changes direction onlywhen flowing at a slow rate or when in a plenum chamber.

Referring particularly to Figure 1 of the drawings, a stream of incomingair passes downwardly through a vertical conduit 2 and into a plenumchamber 4 formed between an upper distributor member 6 welded to conduit2 and a lower plaque member 8. Plaque member 8 is dish-like inconfiguration and member is generally frusto-conical, and the twomembers have lips l0 and i2, respectively, which cooperate to form anannular jet [3 which surrounds plenum chamber ti. Plaque member 8 isheld in place by a screw 14 which extends through a sleeve l6 integralwith the plaque member, and which is threadably received in a fixedsleeve 18 formed in a bracket 20 (see Figure 2). Bracket 29 is formed bytwo strips of sheet metal which are welded together and are positioneddiametrically with respect to conduit 2 with their ends welded to theconduit. As pointed out above screw [4 is threaded into sleeve l8 and itsupports plaque member 8 so that the plaque member may be raised andlowered by turning the screw with a screw driver, and this moves lip Itto and from lip l2. Thus in practice the plaque member is adjustablypositioned to give the desired cross-section to jet 13.

During use a stream of air flows at a rapid rate downwardly throughconduit 2 but the how is steady and is along a straight path so that noappreciable noise is created. At the bottom of the conduit the airenters plenum chamber 4 and is directed horizontally in an annularstream from jet IS. A static-pressure head is maintained in plenumchamber 4 and the size and shape of the plenum chamber is such that theair does not move rapidly within the plenum chamber and there is noappreciable turbulence.

In Figure 3 the shapes of lips Ill and 12 which define jet l3 are shownand the air movements from and around the jet are indicated somewhatschematically. The air paths indicated by the arrows are illustrative ofthe air movements in a radial plane, it being understood that the jet isannular so that in fact air is directed evenly from the entire peripheryof the distributor. The air movement outwardly from jet i3 is indicatedby the straight arrows 22 and adjacent the jet the movement is quiterapid. This outwardly moving stream of air tends to carry with it theair in the zones directly above and below it, with air joining theoutwardly moving stream along two curved planes indicated by the brokenlines 26 and 28, so that between these planes there is an outwardlymoving stream of air of ever-increasing cross-section. Beneath the planeof line air is picked up as indicated by the curved lines 23, and abovethe plane of line 28 air is picked up as indicated by the curved lines24. The increase in the cross-section of the stream of air isaccompanied by a reduction in the speed of flow, and, at the same time,the air joining the outfiowing stream is thoroughly mixed with the airfrom the jet. In this way, as the speed is reduced the temperature andhumidity condition of the stream approaches that of the surrounding air.In addition to the air movements indicated there is a generalcirculation of air in the room, with the flow outwardly from the jetbeing of decreasing intensity, and with the general movement toward thecurved planes represented by lines 25 and 28 being such that the airabove and below the level of the distributor is circulated steadily butwithout there being drafts or cold strata of incoming air.

In spite of the air circulation which is obtained by this distributor ithas been found that there is no substantial flow of air along the bottomsurface of plaque member 8 or along the upper surface of member 6. Themain portion of the air which is mixed with the incoming air flows to azone spaced from the distributor and it does not come into contact withthe distributor. Thus, the top and bottom surfaces of members 6 and 8 donot become soiled by the accumulation of dirt and at the same time athorough mixing action is obtained without excessive turbulence andwithout the objectionable noise referred to above. Under somecircumstances, there may be some flow of air back to lips Iii and I2,and therefore, some accumulation of dirt on the opposing surfaces ofthese lips. However, this dirt may be removed readily, and even if notremoved, it does not interfere with the general neat appearance of thedistributor.

In the embodiment of Figures 1 to 3 the stream of air is directedhorizontally, but under some circumstances it is desirable to direct thestream of air downwardly or upwardly and this is possible by merelyusing a lower plague of a different diameter from that of the upperdistributor member. For example, in Figure 4 plaque 38 is of slightlyless diameter than member 6 so that the stream of air is directeddownwardly at an angle of about 22 /2. the same as explained inconnection with Figure 3, except that the stream is directed downwardlyas indicated. In Figure 5 a plaque 32 is provided which is of evenlesser diameter than plaque 35] so that the stream is directeddownwardly at an angle of about 45. When it is desirable to direct thestream of air upwardly the lower plaque is appropriately larger. Thus,in practice a single upper distributor member 6 may be used selectivelywith any one of a large number of lower plaques so as to obtain thedesired direction of flow, or a number of upper distributors ofdiiferent sizes may be used selectively with a single sized plaque 8 toobtain the same results.

As many possible embodiments may be made of the mechanical features ofthe above invention and as the art herein described might be varied invarious parts, all without departing from the scope of the invention, itis to be understood that all matter hereinabove set forth, or shown inthe accompanying drawings is to be interpreted as illustrative and notin a limiting sense.

I claim:

1. In an air distributor, the combination of, a conduit means forming anair passageway, a first distributor member connected to said conduitmeans and flaring radially outwardly therefrom, a second distributormember of generally inverted conical shape positioned in axial alignmentwith said first distributor member and forming with said conduit meansand said first distributor member a plenum chamber into which the airflows and within which the velocity of the air is substantially reduced,supporting means connecting said second distributor member to saidconduit means, said first and second distributor means presentingopposed converging walls which have substantially greater radii thansaid conduit means tending to direct the air radially outwardly withrespect to said axis, said first and second distributor members havingopposed discharge lips at their outer edges which are curved away fromeach other and form an air distributor jet through which the air isdirected at a rapid rate in a generally radial direction with respect tosaid axis.

Here the mixing action is 2. In an air distributor as described in claim1, wherein said first and second distributor members are outwardlyconverging members and said lips are annular, and wherein saidsupporting means include an axially positioned adjusting screw which maybe turned to raise and lower said second distributor member.

3. In an air distributor as described in claim 1, wherein said seconddistributor member has a Number slightly smaller radius than said firstdistributor 10 member, whereby said lips direct the air radially andaxially with respect to said axis.

ROBERT C. ROBERTSON.

References Cited in the file of this patent UNITED STATES PATENTS ameDate Number N Esty Apr. 21, 1908 Number

